How to concat without column names?
>> df = pd.DataFrame({'col1': [1], 'col2': [4]})
>> df1 = pd.DataFrame([[5,5]])
>> pd.concat([df, df1])
col1 col2 0 1
0 1.0 4.0 NaN NaN
0 NaN NaN 5.0 5.0
Also the types changed into float64 from int64 if you see closely.
Expected
col1 col2
0 1 4
0 5 5
Create same columns names in both DataFrames by DataFrame.set_axis:
df1 = df1.set_axis(df.columns, axis=1)
Or assign columns names:
df1.columns = df.columns
#alternative - got 0,1 columns
#df.columns = df1.columns
Last use concat:
out = pd.concat([df, df1], ignore_index=True)
Temporarily set_axis with that of df on df1:
pd.concat([df, df1.set_axis(df.columns, axis=1)], ignore_index=True)
NB. append is being deprecated, don't use it.
output:
col1 col2
0 1 4
1 5 5
